Action rail assembly



June 23, 1970 ."EIHZI 'HARADA ET'AL 3,516,325

ACTION mun ASSEMBLY Filed April 5, 1968 2 Sheets-Sheet l F'IG. 1

e) Mm A1100! l/ITW' v Jun 3, E|Z I HARADA ETAL 3,516,325

ACTION RAIL ASSEMBLY Filed A rils. 1968 I 2 Shets-Sheet 2 FIG. 2 FIG. 5

United States Patent Oflice Patented June 23, 1970 3,516,325 ACTION RAIL ASSEMBLY Eizi Harada and Kazutoshi Matumoto, Hamamatsu-shi, Japan, assignors to Nippon Gakki Seizo Kabushiki Kaisha, Hamamatsu-shi, Japan, a corporation of Japan Filed Apr. 3, 1968, Ser. No. 718,408 Claims priority, application Japan, Apr. 7, 1967, 42/ 22,221; May 8, 1967 (utility model), 42/ 37,694 Int. Cl. Gc 3/18 US. Cl. 84243 8 Claims ABSTRACT OF THE DISCLOSURE An action rail assembly consists of a metal hammer flange rail having an L-shaped cross section, a regulating wooden rail with a plurality of regulating buttons, and means to connect the wooden rail to the metal rail so as to allow for a slight lengthwise expansion or contraction of the former relative to the latter.

This invention relates to an action rail assembly improved so as to protect a hammer flange rail from the torsion and bending to which it may be subjected by such factors as temperature and humidity prevailing where the piano is situated.

The prior art action rail assembly consisted of a hammer flange rail and a regulating rail rigidly connected thereto, both rails being made of wood. Therefore, the rails were subjected to torsion and bending caused by temperature and humidity prevailing where the the piano was situated.

It was required that the regulating rail should be made of wood so as to permit adjustment by attaching a plurality of buttons thereto. On the other hand, if a hammer flange rail is made of metal it may be protected from torsion and bending, but it can not allow for a slight lengthwise expansion or contraction of the regulating wooden rail relative thereto due to such a rigid adhension between both rails as was the case with the prior art.

An object of this invention is to provide an action rail assembly improved so as concurrently to protect it from torsion and bending to which it may be subjected by temperature and humidity, and to allow for a slight lengthwise expansion or contraction of the regulating rail relative to the hammer flange rail.

In an aspect of this invention, the action rail assembly consists of a metal hammer flange rail having an L-shaped cross section, a regulating wooden rail with a plurality of regulating buttons, and means to connect the wooden rail to the metal rail so as to allow for the a slight lengthwise expansion or contraction of the former relative to the latter.

In this case, the connecting means may consist of a metal screw for use in wood, a spring washer and a cylindrical collar loosely surrounding the wooden screw. An expansible or elastic adhesive may be employed as a connecting means instead of the aforementioned mechanical connector.

The invention will be better understood by reference to the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a sectional view of an action rail assembly embodying this invention, where the rail assembly is incorporated in a piano action mechanism;

FIG. 2 is a sectional view of the action rail assembly broken away along a different plane from that indicated in FIG. 1, showing means for connecting the regulating ing wooden rail to the hammer flange metal rail;

FIG. 3 is a sectional view of another embodiment of the action rail assembly;

FIG. 4 is a perspective view of another embodiment of the hammer flange rail;

FIG. 5 is a sectional view of the hammer flange rail indicated in FIG. 4; and

FIG. 6 is a sectional view of a further embodiment of the action rail assembly.

In FIG. 1, there are provided brackets, one of which is indicated at 11. To the rear ends of the brackets are connected a supporting rail 12 and to the forward ends thereof a hammer flange rail 13. A plurality of wippen assemblies, one of which is indicated in FIG. 1, are disposed on the supporting rail 12. Each of the wippen assemblies includes a wippen pivoted on the rail 12, a repetition lever 14 rotatable on the wippen and a jack 15 also rotatable on the wippen. Hammer shanks 16 are arranged above the wippen assemblies repectively. The forward ends of the hammer shanks 16 are rotatably mounted on shank flanges 17 fixedly secured on the hammer flange rail 13. Hammers 18 are rotatably connected to the rear ends of the hammer shanks 16 respectively. The aforementioned mechanism and operation thereof are similar to those of the prior art device.

The feature of this invention indicated in the embodiment of FIG. 1 is apparent from the following decription of the action rail assembly. The action rail assembly consists of the aforesaid metal hammer flange rail 13 having an L-shaped cross section and perforated with holes in the upper horizontal portion thereof, and a regulating wooden rail 19 having a plurality of regulating buttons.

The hammer flange rail has a platform formed on the upper portion thereof adjacent to the rear side edge as shown in FIG. 2, so that the shank flange are fixedly disposed on the platform. The regulating wooden rail 19 is connected to the hammer flange rail 13 by means of a connecting joint 20. The connecting means consists of a metal screw 21 for use in wood, a spring washer 22 and a cylindrical collar 23. The wood screw 21 is inserted through the hole of the metal rail 13 in a manner to cause the end thereof to extend outside of the rail 13 and the end of the screw 21 is screwed into the wooden rail 19 so as to place between both rails the collar which loosely surrounds the middle portion of the screw 21. Therefore, the wooden rail 19 is connected to the metal rail 13 in a manner to allow for a slight lengthwise expansion or contraction thereof.

FIG. 3 indicates a combination of a hammer flange rail 13a and a regulating wooden rail 19a connected to each other by means of an expansible or elastic adhesive of a synthetic rubber base such as styrene-butadienerubber dissolved in ketone. The adhesive will absorb differential expansions between both rails.

FIGS. 4 and 5 indicate a hammer flange rail 13b modified from those shown in FIGS. 1 and 2. The flange rail 13b has a stage 24 disposed along a line adjacent to the rear side of the upper surface thereof. The stage includes a lengthwise rectangular groove 25 extending along a line adjacent to the forward side thereof. In the rectangular groove 25 formed in the platform is disposed an elongated elastic member 27 formed from, for example, synthetic resin and having a rectangular cross section. The elastic member 27 has a V-shaped slit formed in the exposed surface thereof so as to carry a shank flange guide wire 28 therein. The metal rail 13b further includes a separate lower narrow platform 26 disposed along a line adjacent to the rear side of the platform 24. To the platform 26 is attached by means of an adhesive a friction sheet 29 such as a sand-paper.

FIG. 6 shows a hammer flange rail having an L- shaped cross section. The rear portion of the rail 130 which spreads horizontally sidewise is caused by means of screws 31 to rest on, and is connected to, the upper ends of brackets 11c, one of which is indicated in FIG. 6. The vertically extending forward portion of the rail 130 is connected by means of separate screws 32 to the forward sides of the brackets. A platform formed on the upper surface of the rail 130 has a protrusion 28a integrally formed thereon instead of the wire 28 shown in FIGS. 4 and 5.

The shank flange to be attached to the stage 24 shown inFIGS. 4 and 5 has a V-shaped slit similar to that shown in FIGS. 1 and 2. Therefore, the shank flange is arranged exactly at right angles to the hammer flange rail by fitting a guide wire into the V-shaped slit.

Since a friction sheet or sand paper is provided on the platform, each of the hammer flanges can be prevented from tilting on the platform, even if it is fixed with a single screw.

In the aforesaid embodiments, the hammer flange rail is preferably made of metal, for example, aluminum having the desired degree of affinity for wood. The hammer flange rail preferably has a plurality of parallel grooves 33 formed in the outer surface thereof as shown in FIGS. 4 and 5, to prevent work tools from slipping along the surface of the metal rail, with the resultant spoiling of its appearance and camouflage scratches caused by tool-slip trails.

While the invention has been described in connection with some preferred embodiments thereof, the invention is not limited thereto and includes any modifications and alterations which fall within the scope of the invention.

What we claim is:

1. An action rail assembly consisting of a metal hammer flange rail having an L-shaped cross section; a regulating wooden rail having a plurality of regulating buttions; and means connecting the wooden rail to the metal rail with a predetermined spacing therebetween to allow for a slight variation in length of the wooden rail relative to the metal rail substantially without deforming the metal rail.

2. An action rail assembly as claimed in claim 1 in which the connecting means comprises a metal screw passing through said metal rail and threadably engaging said wooden rail; and a collar loosely surrounding said screw and disposed between said wooden and metal rails to provide said predetermined spacing.

3. An action rail assembly as claimed in claim 1 further comprising a plurality of brackets; and screw means securing the hammer flange rail to said brackets.

4. An action rail assembly as claimed in claim 1 in which the hammer flange rail has a platform formed on the upper portion thereof, and is provided with a protrusion on said upper portion adjacent to the forward side of said platform, said protrusion being received by a hammer shank flange to positively locate said hammer shank flange on said platform.

5. An action rail assembly as claimed in claim 1 in which the hammer flange has a platform formed on the upper portion thereof, a rectangular groove being formed in said platform; and an elastic member having a rectangular cross section located in said groove, a small V-shaped slit being formed on the upper surface of said elastic member for receiving a guide wire therein, said guide wire being received by a hammer shank flange to positively locate said hammer shank flange on said platform.

6. An action rail assembly as claimed in claim 1 in which the upper portion of said hammer flange rail includes a stage consisting of an upper platform and a lower platform, said lower platform being located adjacent to the rear side of the hammer flange rail, a rectangular groove being formed in said upper platform; and an elastic member having a rectangular cross section located in said groove, a small V-shaped slit being formed on the upper surface of said elastic member for receiving a guide wire therein, said guide wire being received by a hammer shank flange to positively locate said hammer shank flange on said platform.

7. An action rail assembly as claimed in claim 1 in which the hammer flange rail has a plurality of substantially parallel grooves formed in the outer surface thereof to prevent work tools from slipping along the surface of the metal rail.

8. An action rail assembly as claimed in claim 1 comprising a plurality of said connecting means spaced along the length of said rails.

References Cited UNITED STATES PATENTS 872,551 12/ 1907 Anderson 84239 882,288 3/1908 Billings 84250 1,097,696 5/1914 Werolin 84-237 3,397,604 8/1968 Seybold 84237 X RICHARD B. WILKINSON, Primary Examiner J. F. GONZALES, Assistant Examiner US. Cl. X.R. 84250, 251 

